Effects of a NiFe/MgO interface on the thermoelectric transport behavior of spin-polarized electrons

• Published in: Materials letters 2014-12, Vol.137, p.351-353
• Main Authors: Cao, Yi, Wang, Li-Jin, Feng, Chun, Zhang, Jing-Yan, Yang, Feng, Li, Shao-Wei, Jiang, Shao-Long, Liu, Yang, Yang, Guang, Zhao, Chong-Jun, Song, Fu, Zhou, Zhong-Fu, Yu, Guang-Hua
• Format: Article
• Language: English
• Subjects: Anisotropic magneto-thermopower; Annealing; Interfaces; Interfacial oxygen migration; Intermetallics; Iron compounds; Magnesium oxide; Magnetic materials; Multilayer structure; Nickel base alloys; Nickel compounds; Thermoelectricity; Transport
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2014.09.011

The effects of an NiFe/MgO interface on the thermoelectric transport behavior of spin-polarized electrons were studied by measuring the Seebeck coefficient (S) and anisotropic magneto-thermopower (AMT) of an MgO/NiFe/MgO multilayer structure. Thermally annealing this multilayer was found to increase S (343% at 450°C) through crystallization of interfacial MgO, which allows conductive electrons to achieve better specular scattering at the interface. The AMT was also increased by annealing (139% at 450°C), but this is ascribed to a chemical metallization of interfacial Fe in which the deposition-induced oxygen atoms migrate out of the NiFe layer. This helps to recover the magnetization of NiFe, thereby causing spin-dependent thermoelectric transport behavior at the interface. •NiFe/MgO interface can affect thermoelectric behaviors of spin-polarized electrons.•Seebeck coefficient rises as the interface crystallizes for a better specular scattering.•Anisotropic magneto-thermopower will alter if interfacial chemical status changes.